Sheet metal push on fastener with stud biting teeth



I. SlSLlK May 22, 1956 SHEET METAL PUSH ON FASTENER WITH STUD BITING TEETH Filed June 10, 1952 INVENTOR 4mm Szszzk 44,44 *zdx' v ATTORNEYS BY y FIG.5

SHEET METAL PUSH, N FASTENER WITH STUD BITING TEETH lvan Sislik, Bound Brook, N. 'J assignor to The Palnui Company, Irvington, J., a corporation or N ew Jersey Application June 10, 1952,seriaiiye. $2,610

' 2 Claims. e1; SSH-36) This invention relates to fastening devices and, more particularly, to so-called push on? fasteners made 'of Such fasteners have no thread and ired a s patefifo comprises an elongated b'ody arched upwardly (away from the surface against which it bears) between its ends, the bodybeingpr'ovided with a stud-receiving aperture. The aperture is extended longitudinally of the body and defines a long finger and an oppositely positioning short finger terminatingat their-free ends at opposite sides of the aperture and lying along the center linetof the body, each of these fingelfi being bent upwardly from-the body at an acute angle. The free end of the long finger terminates substantially above the level of the free end of the short finger so as to engage a stud at a point more removed from the body than the engagement ofthe short finger with the stud. Preferably, the ends of the" body areof complemental convex-concave form to increase theeffective length of the body without, a corresponding increase of material required andthe long finger is tapered in width towards its free end.

Among the objects of the present invention are to provide an improved push-on fastener which has superior holding power, which is compact; which willresiliently resistdisplacement' to a marked degree, which is easily and cheaply manufactured as'a unitary sheet metal stamp- 1 My invention is clearly. defined in the appended claims,1

Where parts are for clarity and convenience referred to on the basis of their orientedposition shown in the acc'ompanying drawings,- no limitation as to positioning of the structure is to be implied, since itqwill be understood "that the fastener may be placed in: any position. Also, in 'both the description and the claims, parts at times may be identified by specificnames'forclarity and convenience, but such nomenclatureis to be understood as having the broadest meaning consistent with the context and with the concept of my invention as distinguishedfrom the perti'nent prior art. The best form in which I have contemplated applying my invention is illustrated in the accompanying drawing forming part of thisaspecification, in

which: v V

Fig. l is a top perspective view or a push-on type fastener embodying the present invention.

Fig. 2 is a top plan view of the fastener of Fig. 1', the

outline of contiguous fasteners stamped from a single strip ,of springy metal being shown in broken lines.

t Fig. 3 is a somewhat diagrammatic assembly view showing the fastener in the first stage ofas'sembly with a stud and plate, the fastener being shown in longitudinal section and the plate and trim being shown in section.

a Fig. 4 is a view similar to Fig. 3, the fastener being in the second stage of assembly with the "stud.

Fig. 5 is a viewsimilar to Fig. 4 after completion of application of the fastener to the stud.

Fig. 6 is an assembly view of the fastener of Figs. 1 and 2 assembled with a stud and plate, the fastener and plate being shown in top plan view and the stud being shownin cross section. 1

'Fig. 7 is a view generally similar to Figs. 4 and 5, showing theuse of a tool for applying the fastener to the stud.

Referring now to the drawings, thefastener 10 of the .present invention is formed asa unitary sheet metal stampmetals having the required properties; The fastener corn- 7 prises an elongated body 11 which is arched upwardly between its ends, preferably in an arch 'ofr'nore or less uniform curvature. The side edges 12,? 12 are preferably "parallel, and a series of fasteners may. be stamped successively from an elongated strip of metal, as indicated in Fig.2. 1

The body 11 of the fastener is provided with a studreceiving aperture 14 adjacent one end of the body; the aperture being or such size as to receive a stud of the size and for whichthe fastener is intended. The aperture 14 is shaped as generally indicated in Figs. 1, 2, and 6, the aperture extending longitudinally of the body and defining a long finger 15 and an oppositely positioned the fastener is intended, so that, upon application of the fastener to the stud, only the long andshort fingers are r'eliedon to engage the stud, as will be explained.

Referring now to Figs. 1 3, 4, and 5, the fingers 15 and 16 are bent upwardly (in the same direction as the arch of the body), the long finger preferably bein'g bent up at an angle between 20 and 35 to the plane defined by the extremities of the body. An angle of 32 has worked well in practice. The short fi'nger 16 maybe bentup at a somewhat greater angle, in the order of 60, to such plane. y e 3 The long anger 15 is markedly tapered in width t6- wards its free end 17, the width of thefree end of the finger preferably being approximately one-half of the width of the base 19 of the finger. This taper of the long finger provides. for a more uniform flexing of the finger throughout its length and alse prevents the jamming and sticking of superimposed, loosely packed fasteners before use. This result is enhanced if the side portions 20, 20

of the aperture beside the. long finger 15 are made p'aralv lel with the sideedges 12, 12 of the fastener, a we dgeshaped slug of metal being removed from the fastener body on each side of the long finger 15 so as toprovide an aperture of substantially greater width than the projecting portion of the finger. Moreover, such a construction facilitates manufacture of the fastener, inthat a more uniform stamping can be produced on a production basis thanwould be possible if all of the metal struck from this portion of the body 11 were utilized in forming the finger 15. i

The fastener 11 is adaptedfor assembly with a smooth cylindrical shank or stud. 21 which may be formed of metal or plastic, which should be somewhat softer than the metal from whichthe fastener is formed. Figs. 3, 4,

s, and 1 illustrate the use of the fastener 10 in retaining ornamental trim 22 or the like, such as is found on automobiles, refrigerators, washing nachines, eta, iii pasttion on a platelike or sheetlike member 24, the stud 21 projecting from the back of the trim 22 and through a hole 25 in the member. The free end 17 of the long finger 15 is further removed from the general plane of the body 11 of the fastenerthan the free'end of the short finger 16, the end of this finger being quite substantially above the level of the end of the short finger.

The proportions of the fastener 10 relative to the stud 21 for which it is intended are such that the fastener can be freely passed onto the stud when the fastener is cocked so that the protruding or tail ends or extremities 26, 26 of the base (end removed from the aperture 14) are nearest to the member 24. The distance between the sides 20, 20 of the aperture 14 is substantially greater than the diameter D of the stud 21. Hence, the'sides 20, 20 readily clear the stud as the fastener is passed over it. The distance L between the tips of fingers 15 and 16 is only slightly greater than the diameter D of the stud 21; and when L is geometrically projected onto plane A--A which is tangent to the tips of the fastener, it defines a distance 1 which is less than the diameter D of the stud 21. Thus, the tips of the fingers 15 and 16 will clear the stud 21 when the fastener is in various cocked or inclined positions but will not freely pass down the stud if the fastener is in uncooked position, i. e., with the plane A-A perpendicular to the stud 21. Fig. 3 shows approximately the grestest inclination at which the fastener can be freely passed over the stud, and Fig. 4 shows approximately the least inclination at which the fastener can be freely passed over the stud. This is made possible by the fact that the aperture 14 through substantially its entire length is of greater width than the diameter of the stud 21 and the distance between the free ends of the fingers 15 and 16 is slightly greater than such diameter.

As the fastener is applied tothe stud 21 in cocked position as above discussed, the extremities 26, 26 of body 11 will first engage the member 24 (see Fig. 4). Then, as the fastener 10 is pushed further onto the stud (e. g., by pressing the midportion of the body 11 near the base 19 of the long finger), it is moved to the position shown in Fig. 5, the free ends of the fingers 15 and 16 firmly engaging diametrically opposed sides of the stud 21 at different elevations, the arch of the body 11 becoming somewhat flattened and the contiguous extremity 27 of the body 11 being pressed against the member 24. When applying the fastener, it may be flattenedcompletely against the member 24, the fastener returning to slightly arched condition as shown in Fig. upon removing the application pressure. As the fastener is moved to this latter position, the fingers 15 and 16 become flexed slightly due toengagement with the stud 21, the long finger 15 being flexed much more than the finger 16 due largely to its greater length and the fiexure of both fingers being largely imperceptible to the naked eye. The change in the angularity between the body of fastener and the axis of stud 21 which takes place as the fastener is pressed to fully applied position, together with the greater flexure of finger 17, causethe axial distance along the stud between the points of engagement therewith of fingers 16 and 17 to increase sli htly from the distance d in Fig. 4 to the distance d in Fig. 5.

Preferably, after the fastener 10 is applied to the stud as'indicated in Figs. 3 and 4, it is pressed into locking engagement with the stud by an applying tool 29. The tool 29 is generally cylindrical and has an axial bore 30 adapted to fit closely over the shank 21, the bore terminating at its lower end, as viewed in Fig. 7, in a conical surface of somewhat greater inclination than the long finger providing a peripheral edge portion 31 for engaging the fastener 10 adjacent the base of the finger 15, the tool exerting no pressure directly on either of the fingers 15 or 16. The opposite end of the tool 29 may be provided with a knob-like handle (not shown) for pressing by hand to force the fastener 10 into locking engagement with the stud, the arch of the fastener preferably being completely flattened during application as described in the preceding paragraph.

Referring to Fig. 5, the stud-confronting edge surfaces of fingers 15 and 16 are generally perpendicular to the planes of the fingers and, upon the fingers being bent upwardly as described, the sharp lower corners of these edge surfaces bite into the stud 21 and oppose to a maximum the displacement of the fastener. If the stud-contacting edges of the fingers 16 and 17 were at the same level, they would not grip the stud unless the distance between them were less than the diameter of the stud; and the fastener would be hard to start onto the stud. With the present invention the finger spacing L (see Fig. 3) is greater than the stud diameter and, by canting the fastener, it can be freely slipped onto the stud and then pressed home. The long and short fastener legs, taken with the long and short fingers at difierent levels result in firm gripping of the stud and resilient tensioning of the'stud that is operative over a wide range and is very effective in preventing looseness from developing in the assembly.

The resilience of the body 11 and the value of the fastener for use on more or less uneven surfaces may be enhanced by formingthe ends 26 and 27 of the body in complemental concave-convex form as indicated in the drawings rather than forming the ends straight and at right angles to the side edges 12, 12. Such a form provides a greater length of body without requiring additional metal for production of the fastener. In addition, the cross section of the body throughout its length is more nearly uniform so that, upon application of the fastener to the stud, the flexure of the body throughout its length is more nearly uniform as the arch of the body becomes flattened, thus resulting in a fastener which has greater holding power and is less likely to become fortuitously displaced. The three-point contact of the body 11 of the fastener with the member 24 facilitates the use of the fastener against a more or less curved or uneven surface with less tendency of the fastener to become cocked at an angle to the stud, and also prevents unsymmetrical hearing of the body of the fastener against such a surface.

The fastener of the present invention is of particular value in the retention of ornamental trim under conditions of vibration. The resilience of the body 11 of the fastener 10 will hold the trim 22 tightly against the member 24 so as to prevent vibration of the trim and, in the event that the trim is fortuitously displaced outwardly from the member so as to slightly withdraw the stud, the fastener will draw it tightly back into position.

I claim: I

1. A threadless, push-on fastener for resiliently retaining-a smooth-surfaced stud against withdrawal through a stud-receiving hole in a member, said fastener comprising a single piece of springy sheet metal comprising an elongated body arched upwardly between its ends and having generally parallel sides, one end with a broad axially extending projection with a convex tip thereon, and the other end with a centrally located recess complementary to said projection, the body having a stud-receiving aperture, said aperture extending longitudinally of the body and defining a long finger and an oppositely positioned short finger projecting from the convex side of the body, the fingers terminating at their free ends at opposite sides of the aperture and lying along the longitudinal center line of the body, each finger being bent upwardly from the body at an acute angle and having a sharp corner at its free end for engaging the stud, the angle which the short finger makes with the body markedly exceeding the angle which the long finger makes with the body, the free end of the long finger terminating substantially above the level of the free end of the short finger, the distance between the free ends of the fingers exceeding the diameter of the stud but the geometrical projection of such distance upon a plane tangent to the tips of the body being less than the diameter of the stud, so that, upon application of the fastener to the stud, the tip of the body nearer the long finger will first contact the member and the pressing of the midportion of the body to force the opposite tip of the body into contact with the member will flatten the arch of the body and urge both fingers into tight locking engagement with the stud.

2. A threadless, push-on fastener for resiliently retaining a smooth-surfaced stud against withdrawal through a stud-receiving hole in a member, said fastener comprising a single piece of springy sheet metal comprising an elongated body arched upwardlyvbetween its ends, one end having formations located at the opposite corners of the fastener which extend lower than the other portions of that end of the fastener, the body having a stud-receiving aperture located nearer a first tip of the body than to the second tip thereof, said aperture extending longitudinally of the body and defining a long finger extending longitudinally of the body from the edge of the aperture adjacent the second tip of the body and an oppositely positioned short finger extending longitudinally of the body from the edge of the aperture adjacent the first tip of the body, the fingers terminating at their free ends at opposite sides of the aperture and lying along the longitudinal center line of the body, each finger being bent upwardly from the body at an acute angle and having a sharp corner at its free end for engaging the stud, the angle which the short finger makes with the body markedly exceeding the angle which the long finger makes with the body, the free end of the long finger terminating substantially above the level of the free end of the short finger, the distance between the free ends of the fingers being greater than the diameter of the stud but the distance between the free ends of the fingers projected upon a plane tangent to the tips of the body of the fastener being less than the diameter of the stud, whereby upon application of the fastener to the stud the second tip of the fastener body will first contact the member and the pressing of the midportion of the body of the fastener to force the opposite tip of such body into contact with the member will flatten the arch of the body and urge both fingers into tight locking engagement with the stud.

References Cited in the file of this patent UNITED STATES PATENTS 295,960 Dusen Apr. 1, 1884 312,943 Winans Feb. 24, 1885 334,790 McTighe Jan. 26, 1886 1,276,882 Davis Aug. 27, 1918 1,515,657 Cochran Nov. 18, 1924 1,614,831 Crofoot Jan. 18, 1927 2,064,091 Tinnerman Dec. 15, 1936 2,082,577 Herschmann June 1, 1937 2,191,780 Tinnerman Feb. 27, 1940 2,236,929 Tinnerman Apr. 1, 1941 2,266,049 Kost Dec. 16, 1941 2,381,315 Smith Aug. 7, 1945 2,401,207 Wagstaff May 28, 1946 

